Latest CMS upgrade error - An item with the same key has already been added in Notifications.Feature.Internal


Just upgraded to latest CMS 11.20.3 from 2 feb.

seems an error in 


When i go in to /episerver and /episerver/cms/ but not in /episerver/cms/admin/default.aspx and not FIND and other modules.

Any idea whats up?
[ArgumentException: An item with the same key has already been added.]
   System.ThrowHelper.ThrowArgumentException(ExceptionResource resource) +60
   System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add) +14338200
   System.Linq.Enumerable.ToDictionary(IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector, IEqualityComparer`1 comparer) +302
   EPiServer.Cms.Shell.UI.Notifications.Feature.Internal.<SubscribeAsync>d__12.MoveNext() +1092
   System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() +32
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +62
   EPiServer.Cms.Shell.CmsModule.CreateViewModel(ModuleTable moduleTable, IClientResourceService clientResourceService) +645
   System.Linq.WhereSelectEnumerableIterator`2.MoveNext() +241
   System.Linq.Buffer`1..ctor(IEnumerable`1 source) +498
   System.Linq.<GetEnumerator>d__1.MoveNext() +118
   System.Linq.Enumerable.ToDictionary(IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector, IEqualityComparer`1 comparer) +196
   EPiServer.Shell.UI.Web.Resources.ModuleDependencySorter.GetStartupModules(IEnumerable`1 modules, String startupModule) +321
   ASP.episerver_shell_views_shared_bootstrapper_aspx.__Render__control5(HtmlTextWriter __w, Control parameterContainer) in C:\webb\x\EPiServer\Shell\Views\Shared\Bootstrapper.aspx:34
   System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +117
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +132
   ASP.episerver_shell_views_shared_sleek_master.__Render__control1(HtmlTextWriter __w, Control parameterContainer) in C:\webb\x\EPiServer\Shell\Views\Shared\Sleek.Master:41

I will try to downgrade ... 

Edited, Feb 04, 2021 14:12

Its a known bug now.

Workaround: downgraded to v 11.20.2 where it works

or got this from DeveloperSupport:

1. Run the query below:

select * from tblNotificationSubscription where SubscriptionKey ='feature://notification/' order by UserName

2. You may find there was one "duplicate" where one email started with a whitespace and one not.
3. Please set Active = 0 for one of the duplicate records, the issue will be gone.

Feb 04, 2021 15:02

Issue is still present in 11.20.4.. Is it one that is being worked on? If it is being caused by content then how do you fix it through the CMS?

Feb 18, 2021 16:31

CMS bug is CMS-18303

But i cant see it is official yet.

If in azure you can send it to dxc support, so they can do the db hack it before the release, then it works.

You can also remove all posts in tblNotificationSubscription which starts with whitespace in email, thats also an options.


Feb 19, 2021 9:32

The script needed to update any identified active users with leading or trailing whitespace can be

UPDATE tblNotificationSubscription 
SET Active = 0
WHERE pkID='[name of identified id's]';

Mar 11, 2021 22:13

The bug fix will be released in CMS UI 13.34, which would be very soon.

Mar 12, 2021 9:16
* You are NOT allowed to include any hyperlinks in the post because your account hasn't associated to your company. User profile should be updated.